| expat | 1.1 | NO | `libexpat1-dev` | `expat` | YES | XML parsing |
| GTest | 1.5 | YES | `libgtest-dev`^ | `gtest` | YES | Test suite |
| BerkeleyDB | 4.8 | NO | `libdb{,++}-dev` | `db` | YES | Historic DB |
| Doxygen | any | NO | `doxygen` | `doxygen` | YES | Documentation |
| Graphviz | any | NO | `graphviz` | `graphviz` | YES | Documentation |
[^] On Debian/Ubuntu `libgtest-dev` only includes sources and headers. You must
build the library binary manually. This can be done with the following command ```sudo apt-get install libgtest-dev && cd /usr/src/gtest && sudo cmake . && sudo make && sudo mv libg* /usr/lib/ ```